there is evidence that some understanding existed as early as 500-428BC in the Greek states. Ancient Some of the earliest evidence that supports an ancient technical understanding of snow movement was produced by the Greeks. Anaxagoras, an ancient Greek notes: "the water in the Nile comes from the snow in Ethiopia, which freezes in the winter and melts in the summer". The upper class Greeks in these city states were shown to have basic understanding of the cooling properties that snow exhibited. Upper class citizens would have hay lined pits dug beneath their homes and bring snow down from the mountains to fill them. Perishable food items could then be stored in these pits for months at a time. The Christian Bible contains numerous passages in its text that express a basic understanding of the hydrological cycle. Each of the following verses shows fundamental ideas behind the hydrological processes. Modern One of the earliest modern records of the snow hydrology practice, was introduced by the geologist, Antonio Vallisnieri around the time of the 17th century. His work Theorized, “That rivers arising from springs in the Italian Alps came from rain and snowmelt seeping into underground channels." The first American research labs were introduced during the 1940s in order to solve the many problems associated with snow movement in the World War II era. These three labs were: Central sierra Snow Laboratory (CSSL) Upper Columbia Snow Laboratory (USCL) Willamette Basin Snow Laboratory (WBSL) Currently there are hundreds of snow hydrology labs and sensing devices placed throughout the world. As of 2004, every continent was under observation with the exception of Antarctica. Since then, several sensing devices have been established in the Arctic Circle, allowing for constant observation. Using these in part with satellite imaging systems has produced an accurate depiction of underlying landmass, which was unknown in the past. Hydrologists Snow hydrologists focus specifically on movement and composition of snow and ice, within the field of hydrology. The knowledge gained from this career is most commonly used in weather forecasting and ecological/ agricultural jobs, which require knowledge about the effects of snow migration. They retrieve the information they need through depth, density, and composition readings, as well as various remote sensing techniques. Workers in this field can work for government agencies, research firms and public information services. Equipment and Testing Terrestrial Measurements The study of snow and glacial movement, though now